Crystallographic and magnetic alignment in die-upset Nd-Fe-B magnets

Fully dense and aligned Nd-Fe-B permanent magnets can be prepared from melt-spun amorphous ribbons by a two-step process involving hot compaction and hot deformation. It is the latter processing step that produces alignment. During hot deformation, the randomly oriented and equiaxed Nd2Fe14B grains change to platelet shaped grains such that their crystallographicc axes lie normal to the flat surfaces. The final microstructure of the die-upset …